WASHINGTON – A national anti-marijuana group is blaming Colorado as one of the states propelling a rise in marijuana use among the U.S. workforce.

That follows a new medical laboratory report showing that usage of cocaine, methamphetamine and marijuana is rising in the national workforce.

States that legalized marijuana showed the biggest increases in pot use among workers, says the report by Quest Diagnostics Inc., one of the nation’s biggest drug-testing laboratories.

Those include Nevada, with a 43 percent increase; Massachusetts, up 14 percent; and California, with an 11 rise.

Yet fewer American workers tested positive for opioids and other prescription painkillers in 2017, Quest Diagnostics found.

But the rate of marijuana usage – even in “safety-sensitive” jobs, such as airline pilots and medical personnel – rose 39 percent in Nevada, 20 percent in California and 11 percent in Massachusetts.

“This data mirrors the results we saw when Colorado and Washington legalized marijuana and are numbers we can expect to see any time a state foolishly follows their example,” said Kevin Sabet, president of the anti-pot group Smart Approaches to Marijuana. “Do we want our pilots, doctors and truck drivers stoned? We have to slow down this reckless experiment of pot legalization.”

Smart Approaches to Marijuana seized on the Quest Diagnostics report to advocate against legalization of recreational marijuana sales.

A safety-sensitive job is one in which workers could endanger people’s safety if influenced by drugs or alcohol, the U.S. Labor Department says. Examples include heavy equipment operators, hazardous chemical handlers, pilots and medical personnel.

The number of job applicants testing positive for illicit drugs last year was 4.2 percent, the same as in 2016 but significantly higher than the 3.5 percent of workers tested in 2012, Quest Diagnostics reported. Its report was based on more than 10 million urine tests conducted for employers.

Smart Approaches to Marijuana said states such as Colorado, which don’t prevent some people from carrying marijuana across state lines, can be blamed for part of the increased pot use.

“This data is indeed troubling, but it is not surprising,” Sabet said.

But U.S. Rep. Ken Buck, R-Windsor, suggested marijuana use among workers is determined by individual decision-making rather than political policies.

“It’s simple,” Buck told Colorado Politics. “If an employee is prohibited from using certain drugs while doing their job, then they shouldn’t use those drugs while doing their job, whether those drugs are legally or illegally acquired.”

Quest Diagnostics urged government officials to heed the findings.

“We encourage policy analysts to track these trends closely to determine whether a correlation between the state legalization of marijuana and increased workforce drug use, as suggested by our data, bears out in other research,” said Barry Sample, Quest’s senior director of science and technology.

Smart Approaches to Marijuana used the study as a second opportunity in two months to criticize Colorado and other states for recreational marijuana legalization.

In March, the group released a report showing alarming increases in marijuana use among young people:

“Since Colorado, Washington, Oregon, Alaska and the District of Columbia legalized marijuana, past-month use of the drug has continued to rise above the national average among youth aged 12-17 in all five jurisdictions.”“Colorado currently holds the top ranking for first-time marijuana use among youth, representing a 65 percent increase in the years since legalization (in 2012).“Colorado toxicology reports show the percentage of adolescent suicide victims testing positive for marijuana have increased.”“A study in Colorado found that about 50 percent of youth in outpatient substance abuse treatment reported using diverted marijuana.”